The study is being conducted to obtain data on PDQ (Physician Data Query) database user populations and their satisfaction with the data. The objectives of the study are to survey PDQ database users to 1) obtain information on who is using the database and who is using the information from the database in order to characterize PDQ users; and 2) determine how the information was used, users' satisfaction with the information they received from the database, and users' satisfaction with the method of retrieval, e.g. CD-ROM, online, hard copy. PDQ is available from a variety of database vendors and in an ever growing variety of dissemination formats. While it appears that use of PDQ increases with each additional method of dissemination, the NCI has not surveyed current PDQ users specifically to determine who is using the system and if the users are satisfied with the data they receive. NCI's efforts to increase user satisfaction by adding features to the database and the marketing efforts to increase target audiences have been made on assumptions about needs rather than data on these issues. Increased use has been taken as a proxy for satisfaction, but this has not been formally tested. The following information will be gathered from current PDQ users who will be identified by a password, account, subscription, etc. from lists of PDQ users provided by the database vendors: determination of user status as primary or secondary; determination of type of user, e.g. physician, librarian, etc.; number of other users to who information is distributed; determine for what purpose the PDQ information is used, e.g., to give to a patient or for treatment information; type, i.e., protocols, directory, statements, and amount of PDQ information typically requested; how much PDQ information is used as a proportion to that sent; was the information used as part of a decision process; satisfaction with the PDQ system, both from a technical/software perspective as well as from an informational/content perspective; knowledge of updates/changes to the database; and suggestions for PDQ improvements. The final products will be a written report summarizing the activities and analyses of the project, data tapes and documentation of all questionnaire responses, and a computerized system of data collection, tabulation, and analysis.